In various applications, it is often desirable to effect simultaneous switching of different switching units, such as circuit breakers, supported relative to one another on a common panel or frame. Interconnecting the switch handles of the respective switching units enables movement of one switch handle to cause the similar movement of all the switch handles thereby causing the respective switching units to be simultaneously actuated. In a common application, the switch handles of separate circuit breakers may be coupled together to enable simultaneous switching. The coupling of circuit breakers is useful in applications where circuits must be protected by separate circuit breakers but where it is still desirable, or even necessary, for the conducting states of the individual circuits coupled to all the circuit breakers to be uniformly switched from one state to another.
Various arrangements have been utilized to interconnect handles of adjacent circuit breakers to permit simultaneous switching. However, none of the conventional arrangements have been particularly satisfactory.
Conventionally, the switch handles of adjacent circuit breakers have been connected by a tie pin inserted through aligned holes in adjoining switch handles to couple the handles together. In the conventional systems, however, the tie pin is axially dimensioned to extend through the aligned holes in the adjacent handles so that the end portions of the tie pin protrude beyond the respective handles at both outer ends. To retain the tie pin in position, separate retainers are required at both ends of the tie pin to prevent axial movement of the pin through the holes in handles. For this purpose, a separate retaining ring has been removably secured to each of the protruding ends of the tie pin. In an alternative arrangement, a tie pin having an integral head fixed at one end of the pin is employed so that the head is provided on one of the protruding ends of the pin while a removable retaining ring is secured to the other protruding end to prevent the pin from falling out. In still another arrangement, a rivet having an integral head fixed at one end is passed through the aligned holes in the handles for riveting a sheet metal brace or handle tie in position on the handles with both the head and crimped end of the rivet projecting outwardly from the ends of the handles. In yet another embodiment, a metal clamp is secured to the outer surface of the switch handles by staking the ends of the clamp into the holes of the switch handles along the outer end surfaces of the switch handles. In each of the conventional arrangements, however, the handle tie or brace used to interrconnect the switch handle protrudes beyond the outer ends of the handles. In many applications, the protruding ends of the handle tie result in an undesirable arrangement. For example, not only are the protruding ends of the handle ties aesthetically unpleasing, but in certain applications, the protruding ends may interfer with the operation of the circuit breaker by impeding switch movement through inadvertent contact with external objects. Another draw back with the conventional arrangements is that a retainer whether it is an integral head or a removably retaining ring, must be used at both ends of the tie pin.
Other conventional arrangements have utilized tie pins having tangs for anchoring into the switch handle. One of the problems with using anchoring tangs for securing a tie pin to a switch handle is that the handle material must be relatively soft. Otherwise, the anchoring tang will have a tendency to crack the switch handle as the tang digs into the handle during the insertion of the tie pin into the handle opening. In applications where relatively hard materials must be used for the switch handles in order to reduce flamability, for example, the problem of handle cracking caused by the use of anchoring tangs is greatly increased.
In accordance with the present invention, an assembly for coupling switch handles is provided which overcomes the problems inherent with the conventional arrangements. More specifically, the unique assembly for coupling adjacent spaced apart switch handles in accordance with the present invention eliminates the protrusion of the tie pin beyond the ends of the switch handles. As a result, any possibility that the ends of the coupling assembly may inadvertantly catch on adjacent objects or otherwise interfere with the operation of the circuit breakers is eliminated. In addition, by eliminating the protruding ends, the aesthetics of the coupling assembly in accordance with the present invention is greatly enhanced. Further, the need for using separate retainers at both ends of the tie pin in order prevent the pin from moving or falling out of the handle openings is also eliminated resulting in increased efficiency and cost effectiveness. Another problem which is overcome is that the assembly in accordance with the present invention may be used with handles constructed of materials having varying degrees of hardness without any danger of causing cracks or creating large maounts of stress on the switch handles.